Satellite sensor housing

ABSTRACT

A satellite sensor assembly includes a plastic sensor housing that is mounted to a vehicle structure comprised of sheet metal. The sensor housing includes a transversely extending tab that is received within an opening formed in the sheet metal. The tab includes a pair of crush ribs that extend along the length of the tab. The ribs deform as the tab is inserted through the opening to achieve an interference fit. The inference fit serves to hold the housing in place until the housing can be separately fastened to the sheet metal with a fastener.

CROSS-REFERENCE TO RELATED APPLICATIONS

The application claims priority to U.S. Provisional Application No.60/396,353, which was filed on Jul. 16, 2002.

BACKGROUND OF THE INVENTION

This invention relates to a method and apparatus for installing asatellite sensor within a vehicle.

Vehicles include various different sensors that measure a variety ofvehicle characteristics during vehicle operation. For example, sensorsare used to measure vertical acceleration, lateral acceleration,roll-over angular rate, etc. These sensors are mounted at variousdifferent locations throughout the vehicle. A vehicle control unit usesinformation from the various sensors to determine whether conditions areappropriate for deploying a safety restraint device, such as an airbag.

Typically, a main or center tunnel sensor assembly is mounted to avehicle structure at a central location within the vehicle. This centertunnel sensor assembly is used to measure various vehiclecharacteristics that occur near the center of the vehicle. Satellitesensor assemblies are used to measure vehicle characteristics that occurat satellite vehicle locations, i.e., vehicle locations remotelypositioned relative to the center of the vehicle.

The satellite sensors are typically mounted to vehicle structures atlocations remote from a center vehicle position. For example, satellitesensors can be mounted at the front or rear of the vehicle, or can bemounted along the sides of the vehicle near the vehicle doors. Thesesensor assemblies include printed circuit boards and associatedelectronics that are enclosed within a housing.

During sensor installation, the housing is attached to a vehiclestructural component with fasteners. Due to the small size of thesatellite sensor housing and the limited packaging space availablewithin the vehicle, it is often difficult to mount the housing to thevehicle. Two hands are required to properly position the sensor housing,hold the sensor housing in place, and fasten the housing to the vehiclestructure.

Further, during assembly the sensor assembly can be jostled or bumpedagainst adjacent vehicle components. This can loosen sensor andelectronic components mounted within the housing, leading to inaccuratevehicle characteristic measurements.

Thus, there is a need for a satellite sensor assembly that can bequickly and easily installed without introducing unwanted vibrations tothe sensor components during assembly, as well as overcoming the otherabove-mentioned deficiencies with the prior art.

SUMMARY OF THE INVENTION

A sensor housing includes a transversely extending tab that is receivedwithin an opening formed in a vehicle structure in an interference fit.The interference fit holds the sensor housing in the proper orientationand prevents rotation of the housing as the housing is separatelyfastened to the vehicle structure with a fastener.

Preferably, the tab includes a pair of crush ribs that extend in adirection parallel to a longitudinal axis defined by the tab. The crushribs are preferably positioned on opposing sides of the tab. Each crushrib includes a base portion that extends to a crush tip. The baseportion is of greater thickness than the crush tip. As the tab isinserted into the opening, the crush ribs deform in a direction that istransverse to the linear insertion force applied along the longitudinalaxis.

The method for mounting the sensor assembly to the vehicle includes thefollowing steps. The sensor housing is positioned adjacent to thevehicle structure. A housing tab is aligned with an opening in thevehicle structure, and a portion of the tab is deformed during insertionof the tab into the opening to establish an interference fit. Then thesensor housing is fastened to the vehicle structure with a fastener.

The subject invention provides a simplified sensor assembly that can bequickly and easily installed without introducing unwanted vibrations tothe sensor components during assembly. Further, an installer is notrequired to separately hold the housing in place and hold the fastenerin place during the fastening step. These and other features of thepresent invention can be best understood from the followingspecifications and drawings, the following of which is a briefdescription.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a vehicle incorporating a plurality ofsensor assemblies.

FIG. 2 is an exploded view of a sensor assembly incorporating thesubject invention.

FIG. 3 is a schematic view of a vehicle structure to which the sensorassembly is mounted.

FIG. 4 is a front view, partially broken away, of a sensor housingincorporating the subject invention.

FIG. 5 is a side view, partially broken away, of a sensor housingincorporating the subject invention.

FIG. 6 is an installed view of the sensor housing incorporating thesubject invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

As shown in FIG. 1, a vehicle 10 includes various different sensors,shown generally at 12, which measure a variety of vehiclecharacteristics during vehicle operation. These sensors 12 are mountedat various different locations throughout the vehicle 10. A vehiclecontrol unit 14 uses information from the various sensors 12 todetermine whether conditions are appropriate for deploying a safetyrestraint device 16, such as an airbag.

The sensors 12 preferably include a main or center tunnel sensorassembly 12 a that is mounted at a central location within the vehicle10. This center tunnel sensor assembly 12 a is used to measure variousvehicle characteristics that occur near the center of the vehicle.Satellite sensors 12 b are typically mounted at locations remote fromthe center vehicle position. The satellite sensor assemblies 12 b areused to measure vehicle characteristics that occur at satellite vehiclelocations, i.e., vehicle locations remotely positioned relative to thecenter of the vehicle 10. Together, the sensors 12 a and 12 b measurevehicle characteristics such as vertical acceleration, lateralacceleration, roll-over angular rate, etc., for example, and generatecorresponding sensor signals representative of these characteristics.

Preferably, each sensor assembly 12 includes a housing 18, at least onesensor component 20, a printed circuit board (PCB) 22, and associatedsensor and control electronics 24. The sensor component 20, PCB 22, andelectronics 24 are enclosed within an inner cavity 26 defined by aninner surface 28 of the housing 18.

The housing 18 includes a mounting portion 30 with an aperture 32 thatreceives a fastener 34, see FIG. 2. The housing 18 also includes a tab38 that extends outwardly from an exterior surface 36 of the housing 18.The aperture 32 is open to the exterior surface 36 and is positionedadjacent to the tab 38.

The housing 18 is mounted to a vehicle structure 40, shown in FIGS. 2and 3, that is preferably a sheet metal structure. The tab 38 isreceived within a first opening 42 formed in the vehicle structure 40 inan interference fit. The interference fit holds the housing 18 in theproper installation orientation until the housing 18 can be separatelyand securely fastened to the vehicle structure 40 with the fastener 34.The interference fit also prevents the housing from spinning orvibrating during the fastening assembly step.

The vehicle structure 40 includes a second opening 44 that receives thefastener 34. During installation, the tab 38 is fit into the firstopening 42, which simultaneously aligns the aperture 32 with the secondopening 44 in the vehicle structure 40. Preferably, the first opening 42is slot-shaped and the second opening is circular, however, other shapescould also be used.

The tab 38 includes at least one extension member 50 that extendsoutwardly from an exterior surface 52 of the tab 38, see FIG. 4.Preferably, a pair of extension members 50 is formed on the tab 38, withone extension member 50 being positioned on one side 54 of the tab 38and the other extension member 50 being positioned on an opposite side56 of the tab 38. Each extension member 50 includes a base portion 58that extends to a distal tip 60 to define an extension member height.The base portion 58 is thicker than the distal tip 60. Preferably, atapered surface 62 extends from the base portion 58 to the distal tip60, to form a triangular shape.

The housing 18, tab 38, and extension members 50 preferably formed froma plastic material. The extension member height, together with theheight of the tab 38, define a diameter that is greater than thediameter of the first opening 42. Thus, the tab 38 is inserted into thefirst opening 42, the extension members 50 are permanently orplastically deformed or crushed to form the interference fit between thehousing 18 and the vehicle structure 40.

As shown in FIG. 5, the tab 38 defines a longitudinal axis 64 thatextends along the length of the tab 38. The tab 38 includes a baseportion 66 that extends to a distal tip 68. The distal tip 68 preferablyincludes a chamfered or tapered surface 70 to facilitate insertion andalignment of the tab 38 into the first opening 42. A bore 46 ispreferably formed within the tab 38 for weight reduction.

The extension members 50 are preferably formed as crush ribs 72 thatextend in a direction parallel to the longitudinal axis 64. Each rib 72includes a first end 74 that is positioned adjacent to the distal tip 68of the tab 38 and a second end 76 that is positioned adjacent to thebase portion 66 of the tab 38. The ribs 72 have a minimum height at thefirst end 74 and a maximum height at the second end 76, with a taperedupper edge surface 78 extending along the ribs 72 from the minimumheight to the maximum height. This defines a variable height of the ribs72 along the length of the ribs 72. This allows a reduced insertionforce for the tab 38 into the first opening 42 but still achievessufficient deformation of the ribs 72 to achieve the interference fit.

As shown in FIG. 6, the tab 38 is inserted into the first opening 42with a linear insertion force applied in a direction parallel to thelongitudinal axis 64, as indicated with arrow 80. As the tab 38 isinserted into the opening 42, the ribs 72 are crushed or deformed in adirection transverse to the longitudinal axis 64, as indicated by arrows82.

The subject invention provides a sensor assembly 12 that can be quicklyand easily installed within a vehicle with minimal installer handling.Although a preferred embodiment of this invention has been disclosed, aworker of ordinary skill in this art would recognize that certainmodifications would come within the scope of this invention. For thatreason, the following claims should be studied to determine the truescope and content of this invention.

1. A sensor assembly comprising: a housing having an exterior surface and an interior surface defining an inner cavity, said housing including a tab extending outwardly from said exterior surface and at least one aperture open to said exterior surface wherein said tab includes at least one extension member that deforms in response to an insertion force applied to said tab as said housing is mounted to a vehicle structure, said tab defining a longitudinal axis with said extension member deforming in a direction that is transverse to a linear insertion force applied in a direction parallel to said longitudinal axis and wherein said at least one extension member comprises a crush rib extending in a direction parallel to said longitudinal axis; at least one sensor component mounted within said inner cavity wherein said sensor generates a signal representative of a vehicle characteristic; and at least one fastening element received within said aperture for attachment to the vehicle structure.
 2. An assembly as set forth in claim 1 wherein said crush rib includes a base portion that extends to a reduced cross-section distal tip to define a rib height, said base portion being formed with said tab.
 3. An assembly as set forth in claim 2 wherein said crush rib includes a first end adjacent a distal tip of said tab and a second end adjacent said exterior surface of said housing, said first end extending to said second end to define a rib length, and wherein said rib height varies from said first end to said second end.
 4. An assembly as set forth in claim 3 wherein said crush rib has a minimum rib height at said first end and a maximum rib height at said second end with a tapered upper rib surface extending from said minimum rib height to said maximum rib height.
 5. An assembly as set forth in claim 2 wherein said at least one extension member comprises first and second crush ribs extending in a direction parallel to said longitudinal axis on opposing sides of said tab.
 6. An assembly as set forth in claim 2 wherein said housing, said tab, and said extension member are formed from a plastic material and wherein said vehicle structure is formed from sheet metal.
 7. An assembly as set forth in claim 2 wherein the vehicle structure includes a first opening aligned with said aperture and a second opening aligned with said tab.
 8. An assembly as set forth in claim 7 wherein said crush rib and said tab define a first diameter and said second opening defines a second diameter that is less than said first diameter such that said tab as received within said second opening in an interference fit in response to deformation of said crush rib.
 9. A method for mounting a sensor assembly to a vehicle structure comprising the steps of: (a) positioning a sensor housing adjacent to a vehicle structure; (b) aligning a housing tab with a first opening in the vehicle structure and aligning a housing opening with a second opening in the vehicle structure; (c) deforming a portion of the housing tab during insertion of the housing tab into the first opening to achieve an interference fit and forming the portion of the housing tab to include at least one crush rib extending outwardly from the housing tab wherein the crush rib extends in a direction parallel to a longitudinal axis defined by the housing tab; and (d) fastening the sensor housing to the vehicle structure by inserting a fastener through the housing opening and into the second opening, and performing step (c) before step (d).
 10. A method as set forth in claim 9 including the steps of forming the sensor housing from plastic and the vehicle structure from sheet metal.
 11. A method as set forth in claim 9 including the steps of forming the crush rib with a base portion that extends to a distal tip with the base portion having a greater thickness than the distal tip.
 12. A method as set forth in claim 9 including the step of deforming the rib in a direction transverse to a linear insertion force applied in a direction parallel to the longitudinal axis as the tab is inserted into the opening.
 13. A method as set forth in claim 12 including the step of forming a pair of crush ribs on opposing sides of the tab.
 14. A method as set forth in claim 9 wherein step (d) is performed independently from step (c). 